It seems you are a little misinformed as to what type of site deviantART is. Unlike sites like imgur, photobucket, and tinypic, dA is not simply an image hosting site. Images are hosted here, but it is expected that every image a user uploads is a product of their own artistic merit or that of someone who has given them express permission to upload it here.
As you've probably already noticed the community here takes this quite seriously and uploading art that is not yours, whether you claim it is or give credit to the actual artist, is against dA's rules and code of conduct.
You simply need to remove any art that is not yours or that you do not have express permission to upload and you'll be in the clear. Your uploads will be reported if they are suspected of being stolen or dishonestly presented, though, which could result in a permanent ban of your account.
I'm not a mod or admin, just a concerned fellow dA user. It's very possible that you simply made a mistake and weren't aware of how deviantART works. The full rules are available on the site and in the FAQs.